Place Box_Selector on top of Sword first spr_Boxes. Please make sure Box_Selector stays on Z order at TOP or you will not see it.
Click on spr_Boxes and create Instance Variable, call it Boxes_ID.
Boxes_ID = 1
Boxes_ID = 2
Boxes_ID = 3
When you add this to your Hud_Bar look like below:
Now create sprite 96 x 16 in any colour of your choice and name it Health_Bar. Place this Health_Bar on Hud_Bar. Look like below
That is all for our Hudbar. Next we will add code how to manipulate or control Box_Selector. For this create new event sheet, name it Hudbar Events.